Sergeant Preston of the Yukon, or Challenge of the Yukon was a long-running radio series that began on Detroit's station WXYZ (as had The Lone Ranger and The Green Hornet), and an example of a Northern genre story.
From 1951 to 1958 Dell Comics published 29 issues of Sergeant Preston of the Yukon. The first four issues appeared bi-annually, then quarterly, in the weekly catch-all series, Four Color Comics (#344,373,397,419), then assumed its own numbering with issue #5, most-often as a quarterly, but also bi-monthly.
In the comics in this link: Issue 01 is # 344, Issue 02 is # 373, Issue 03 is #397, Issue 04 is # 419. Issue 05 is # 05.
The Dell comic book covers were paintings portraying drama or action, featuring Yukon King and Sergeant Preston in exciting scenes. Once the Sergeant Preston of the Yukon television series premiered, the comic book featured photo-covers of the TV series star in character as Sergeant Preston.
Look for .cbr or .cbz files